Locomotive boiler firebox



Feb. 18, 1941- G. J. CHRISTENSON LOCOMOTIVE BOILER FIR'EBQK Filed Jun. 14. 1989 1221 J t i l Patented Feb. 18, 1941 UNITED STATES PATENT OFFICE 2,232,049 LocoMoTiv norms. Fmncox Application June 14, 1939, Serial No. 278,998

2 Claims.

This invention relates to improvements in locomotive boiler fireboxes and particularly to those of the combustion chamber type and it consists of the matters hereinafter described and more particularly pointed out in the appended claims.

Space limitations in the combustion chamber of a locomotive boiler firebox, are such that the conventional type of thermic syphon is not only difficult to install therein but it does not function as efliciently'and it does not have the flexibility desired. Heretofore the top end of the syphon provided a single opening longitudinally of the crown sheet portion of the combustion chamber and its bottom end opened through the bottom sheet portion generally in line with the top end. The syphon so constructed acts as a rigid vertical strut in the combustion chamber which opposes relative movements between the sheet portions of the combustion chamber and which, un-

der certain conditions, induces objectionable stresses therein. When such stresses exceed the elastic limit of the sheet portions of the combustion chamber and the syphon employed therein, fractures occur.

()ne of the objects of the present inventionis to provide a water steaming and circulating element especially adapted for use in the combus- 9 tion chamber ofthe firebox and which is of such flexible construction that it will accommodate relative sheet movement, prevent localizing of stresses and reduce fractures therein.

Another object of the invention is to provide 35 an element for use in the combustion chamber of the firebox, which may be produced at a low cost, and which is so formed that parts may be removed from either or both ends thereof readily to fit the vertical dimensions of the combustion chamber in which it is to be installed.

A further object of the invention is to provide an element for use in a combustion chamber that has its greatest superficial area disposed transversely of the combustion chamber for a better action thereon by the products of combustion and whereby water movement is accelerated through the element to discharge as fountains that insure a washing of the associated top part of the combustion chamber under lower 50 water conditions.

The above mentioned objects of the invention, as Well as others, together with the several advantages thereof, will more fully appear as the specification proceeds.

55 In the drawing:

Fig.3 is a horizontal detail sectional view on an enlarged scale as taken on the line 3-3 of Fig. 1, and

Fig. 4 is a perspective View of the element removed from its position of use in the combustion chamber of a locomotive boiler firebox. 5

Referring now in detail to that embodiment 1 of. the invention illustrated in the drawing: it indicates the crown sheet of the firebox of a locomotive boiler which merges into the side sheets H, and l2 indicates the inner throat sheet of the firebox. The portion 13 of the crown sheet extends forwardly of the plane of the throat sheet to form the top of the combustion chamber [4. This chamber is closed at the front end by a flue sheet I5 and the bottom sheet portion It of the combustion chamber merges into the front end of the inner throatsheet l2.

The boiler sheet is indicated at ll, the outer throat sheet is indicated at l8 and the mud ring, which is indicated at l9 provides the bottom for the front throat 20 which, of course, is in communication with the water space of the boiler. The structure described, which is conventional in a combustion chamber type of locomotive boiler firebox, is staybolted in the usual manner.

In the combustion chamber I4 is located a watersteaming and circulating element that embodies the preferred form of the invention and which; element is indicated as a Whole at 2|. This element as appears in Fig. 4 is somewhat the shape of a tuning fork in that it includes a relatively short perpendicularly disposed bottom and tubular inlet leg 22 and laterally spaced substantially perpendicularly disposed top end tubular outlet arms 2323 preferably of the same diameter as that of but longer than the inlet leg. The bottom ends of said outlets are connected together by a substantially semi-circular junction or crotch 24 and the top end of the inlet neck opens centrally into the bottom of said crotch.

The opposite sides of the top end of the inlet join by inside rounded corners of generous radius with the opposed portions of the rounded bottom of the crotch. This arrangement eliminates any relatively sharp corners at the junction of the inlet and the outlets, so that in use the entire internal surface of the junction crotch is swept clean to prevent deposits of sediment on said surface. In the present instance the outlet arms 23 are shown as diverging upwardly and outwardly from the crotch but this is only to fit the particular arrangement at hand with respect to the position of the stay bolts in the crown sheet portion of the combustion chamber in which the element is installed. If necessary, the said outlets may be brought more nearly toward parallelism by bringing the top ends of said outlet arms closer together, with the bending occurring at the junction or crotch.

To install the element, thus described in the combustion chamber l4, laterally spaced openings 25 are formed in the portion l3 of crown sheet and into which the top end of the associated outlet arms 23 of the element are inserted. A diaphragm 26 is provided in the bottom portion l6 of the combustion chamber into which the bottom end of the inlet leg 22 of the element is inserted. This may be accomplished by moving the outlet arms upwardly through the openings to such an extent that the bottom end of the inlet leg clears the diaphragm, thus permitting the said end to be inserted into the diaphragm. After the element has thus been positioned, the outlet arms are welded as at 21 to the portion [3 of the crown sheet and then the inlet neckis welded as at 28 to the top edge of the diaphragm. With an element of the kind described, only a minimum number of stay bolts need be removed from the crown sheet portion l3 to accommodate an installation as each opening 25 encompasses only four of such bolts asappears in Fig. 3.

It is apparent that the greatest superficial area of the element is disposed transversely to the path of movement of the products of combustion as the same pass through the combustion chamber to the flues. Thus a good absorption of heat units is afforded by the element without choking the passage of the products of combustion through the chamber to such an extent as to produce undue turbulence in the combustion chamber.

The outlet necks being relatively long and being connected by the semicircular junction or crotch of generous radius, have suflicient flexibility to accommodate the relative movement between the top and bottom sheet portions of the combustion chamber.

In the present instance the inlet leg and the outlet arms are shown as having a circular cross sectional shape, but as is apparent, other cross sectional shapes are well adapted for the purpose. Also, in the present instance the element may be made from a pair of counterpart stampings having their like edges arranged in abutting relation and then welded together in the conventional manner as indicated at 29 in Figs. 2, 3 and 4.

While in describing the invention I have referred in detail to the form, arrangement and construction of the parts involved, the same is to be considered only in the illustrative sense so that I do not wish to be limited thereto except as may be specifically set forth in the appended claims.

I claim as my invention:

1. In a locomotive boiler firebox having a combustion chamber defined in part by a crown sheet portion and other sheet portions, a water steaming and circulating element arranged in said combustion chamber and including a plurality of relatively long upper tubular outlets that are spaced apart laterally of the combustion chamher and open at the top end through the crown sheet and are connected together at the bottom end by a curved crotch, said element also including a shorter tubular inlet neck, the top end of which opens into said crotch at a point between the axes of said outlets and the bottom end of which opens through one of said other sheet portions of the combustion chamber.

2. As an article of manufacture, a water steaming and circulating element for use in the combustion chamber of a locomotive boiler firebox, said element being substantially in the shape of a tuning fork and including a pair of relatively long spaced apart tubular outlets joined together by a crotch and a shorter tubular inlet communicating at one end with said crotch.

GUST J. CHRISTEN SON 

